When freight is loaded high in an open-bed cargo truck, the goods often tilt when driving on a slanted road or when making sharp turns. Namely, as the truck slants together with the slant of the road, the weight of the goods loaded in the bed of the truck forces the goods to tilt in the direction of the slant. Centrifugal forces when making sharp turns, especially at high speeds, often causes the same problem. Accordingly, the driver must stop the truck and re-fasten the goods in the bed of the truck in an upright state.
Further, a mix of the right factors--extreme slant in the road, overly top-heavy load, both a slant in the road and a turn in the opposite direction of the slant, high speed turning, etc.--can cause the truck carrying a large load to overturn.